Process of forming fusible phenol resins.



J. W. AYLSWQRTH. PROCESS .0F FORMING PUSIBLB PBENOL RESINS.

1111151.101111011IILLD,MAR.1o.' 1911.

.Patented May 28, 1912 4,5 its forms,

UNITED sTATEs PATENT. OFFICE;

JONASW. AYLSWORTH, F EAST ORANGE, NEW JERSEY, ASSIGNOR OF ONE-HALF T0 FRA-NK L.` DYER, OF MONTCLAIIKR, NEW JERSEY.

Specification of Letters Patent.

Patented May 28,1912.

7 Original application meri-May 14, 1909, Serial'No. 496,060. llivided and this application iled 'March 10,

. 1911. Serial N0. 613,577.

1909,'entitled Composition and process ofV manufacturingthe same.

The application above referred to relates to the formation 0f a synthetic resin, which is a hard fusible resin formed by the condensation Aof a phenol with formaldehyde,

and also the formation of' an ultimate iny fusible phenolic condensation p roduct which is insoluble and very hard. This infusible product maybe formed as described .in the' said application by reaction between the fusible phenol resin and an added amount of formaldehyde. In the said application, several methods are described for forming the fusible condensation product or phenolic resin. My present application concerns itself only with the second method described in myv application above referred to for forming the phenol resin, and also a combi-- nationof the first and second methods for forming the phenol resin, as described in the parent ap -'cation. The object of my invention is to produce .a fusible phenolic condensation product by the process to be described.

In order that my invention may be more I 40 clearl understood, attention is hereby directed tothe accompanying drawing forming part of this specication and illustrati ing diagrammaticallyl one form of apparatusrwherein may be carried out in one of the phenol resin referred to. v With the first method of forming the fusible phenolfresin described in myap'plication above referred to, phenol "or cresol is 15,0,4 heated in anau-bclave to a temperature of from 260 to B40 degrees F.. 'au`dmaintaned y improved method for forming.

at Such temperature. Formaldehyde gas is forced by suitable pumps into the bottom of the autoclave, where it is distributed by means 'of a finely perforated coil into a mul- 55 titude of bubbles which pass `upward through the phenol and are absorbed therein and combinedtherewith. A pressure in slight excess of the vapor tension of the contents of the autoclave is maintained in the autoclave by means of feeding compressed formaldehyde gas therein as rapidly asit Y I combines with the phenol. The 'supply of formaldehyde is continued until a sample withdrawn for test shows only the desired small percentage of free or 'unchanged phenol. A test may be made, as is well understood,by obtaining the fbromin' number of the composition, and the percentage of free phenol, as indicated by the bromin number, may vary from a very' small amount up to 12 per cent. The supply of gas is then vstopped and a vent 'in the autoclave is opened for the escape of steam which is regulated by a suitable valve. The. 7 5

a contents of the chamber are then 'heated to complete 'dehydration which requires about A 400 degree F. of heat. The contents are then cooled o about 240 degrees F. and cast in ingots for subsequent use orv passed into suitable mixing vessels for immediate use.

Referring to the drawing illustrating a means for practisingf the irst `method of forming phenol resin described, formalde- 'hyde is vgenerated in the generator 1,.and 85 passes through condenser 2, which removes unchanged methyl-alcohol therefrom, to the 'gasometer 3, which is provided Mwith anv oil seal and is \adapted to be steam heated.

Formaldehyde gas is taken therefrom as dei; 9.0v i

sired, by pump 4 and allowed to passasz' bubbles from 'perforated pipe 5 into the liquid phenol 6 in the autoclave 7 which 'isprovided with steam jacket 8, agitator 9, pressure gage 10, vent 11 for they ,escape of 95, steam'when necessary, which is regulated by a valt/ell', and safety valve 12. Provision shouldbe made for steam heating theypipes .through which' the'.formaldehyde` passes,

and for passing cooling water through ,1 00 steam jacket 8 when the-reaction has started to prevent 'the temperature from rising l pulverized and then baked at above the proper reaction temperature. This can be regulated by thermometer 13.

In the second of the methods referred to in the parent application, which will be claimed herein, phenol and a 40% solutlon of formaldehyde, together with a small percentage of either an acid or a basic acceleration or catalytic agent, are treated and allowed to interact `to Aform rapidly the ultimate condensation product of the phenol and the formaldehyde in the form of an infusibleL porous mass. This mass will be porous because of the evolution of gaseous products, which as is well known, takes place when the reaction between the phenol and formaldehyde is allowed to rapidly ensue at an elevated temperature and under no counteract-ing pressure. In this case, however, this is of no moment, because of the subsequent treatment of the mass. This infusible mass is preferably crushed and approximatelyT 350 degrees F., whereby entrapped water and acid vapors are expelled.. The powdered and dried substance is mixed with phenol or cresol in approximately the proportion of two parts of the final condensation product to one part of the phenol, and heated in a closed vessel under its own pressure to a temperatureJ` of from 450 to 550 degrees F., for several hours. By this treatment, the ingredients of the mass goy into the solution with a chemical change, whereby the product reverts or is broken down to the fusible resin, presumably by reduction of the formaldehyde element in the combination. By this means after the distillation of the excess unchanged phenol, a resin is formed similar to that described in the process described as the first method in my application above referred to.

In method 2, just described` the ultimate condensation product is entirely converted into phenol resin, there being an excess of phenol, as stated, after the formation of the resin, which may be distilled ofl". Instead of distilling off this excess phenol. however. compressed formaldehyde gas may be forced into the solution, after the ultimate product has been broken down to phenol resin, and caused to combine with the excess phenol, as in the first process, to form more phenol resin, the gas as -fast as it combines with the excess phenol, and this continued, as in the first described process, until a test sample shows the desired small percentage of uncombined phenol. As noted above, under the second method-` acid or basic condensing agents apparently must be used `in small percentages in the formation of the ultimate infusible product which is to be broken down to the fusible condensation product or phenol resin, since being forced into the solution infusible phenolic condensation products formed without such agents do not readily dissolve in the phencl except at much higher temperature.

,It is especially advantageous to ccinbiiie methods 1 and 2, as just described, because thereby a manufacturer is enabled to use scrap material and discarded and imperfect articles. Phenol and cresol are the preferred solvents for the ultimate condensation product, but other solvents may be used, such as a mixture of phenol and naphthalene, the naphthalene in this case being removed by distillation after thc solution is formed, if desired. In this method the -naphthalene is used to dilute the solventl mlxture, and to obviate the necessity ol" using as much free phenol as wouldotherwise be necessary.

The phenol resin obtained by any of the methods described after complete-dehydration and removal of excess phenol is a hard resin, very similar in texture to copal and kauri gum. It is soluble in all proportions in acetone, amyl, ethyl, methyl and butyl alcohol, amyl, ethyl and methyl acetate. acetic acid, acetylene tetra-chlorid, and mono-nitro-benzene, (oil of mirbane), which it remains unchanged 'after evaporation of the solvents. It is fusible and practically unchanged when heated to 420 degrees F. It melts at about 220 degrees F., but has no sharp melting point, passing through vari-- ous degrees of viscosity, until at 250 degrees F. it may readily be poured and at 350 degrees F. it becomes quite thinly fluid. It acts as a weak acid toward bases with which it combines. It is soluble inv shellac` resin and similar substances` when fused therewith. This resin will not form the hard infusible condensation product described by Smith, Story, Baekeland and others, (see English Patents 16,247 of 1899, to Smith, 8875 of 1905, to Story, U. S. Patents 942,699

to Baekeland, and 735,278, to Luft, and an article by W. Kleeberg, in the German publication Annalen (ler Chemie Liebig, vol` 263, page 283, 1891), When heated with basic or acid condensing agents, or alone, at any temperature. When mixed with formaldehyde, paraformaldehyde, or trioxymethylene, and heated, it combines therewith and-forms a hard infusible mass, Which, if not admixed with other bodies, remains transparent and chemically inert, and is insoluble in vater and in the following solvents,4 alcohol, (ethyl, methyl, amyl or butylic), ether, chloroform, carbon bisullid, carbon tetra-chlorid, acetylene tetra-chlorid, acetone, benzol, camphor oil, turpentine, melted waxes, petroleum, and mineral and vegetable oils. It will not, however, form p such hard infusible mass when mixed with aldchydes in general, lother than those mentioned, and if the percentage of formaldehyde or its polymers exceed 7% per cent., the excess escapes as bubbles in the mass and renders the latter useless for some purposes.

In addition to methods 1 and 2 and the combination thereof previously described for forming phenol resin, I may, as stated in my application above referred to, use a formaldehyde to 1000 parts of phenol. yIn the above proportions, formaldehyde solutions are given as volume percentages. The weight percentage of the formaldehyde in thesolution is 'approximately 5% less. The proportions' of formaldehyde solution given in the formulas are slightly more than the required amount to allow fcr llosses during the process. In this method as in method No. 1 above described, care must be taken to avoid the presence of any impurity which will act as an accelerator or catalytic-agent, otherwise diilicultly fusible,and very visoidproducts will result. .For instance, if the operation is carried out in an ironvessel, care must be taken to have the iron well enameled or lined with a metal which will not modify the product.

Iron and lead so 'Y modifythe product as to render the latter tioned application.

fusible insoluble phenolic unfit. If crude phenol or cresol are used, l they 4should rst be refined by distillation to eliminate basic metallic impurities as well as mineral acids. `In process No. 2 above described, for making phenol resin, when naphthalene and phenol are used as a solvent for the ultimate condensation product to be transformed or broken down into the phenol resin, the phenol must be added in the proportion of about 20% of the condensation product and the naphthalene in about the proportion of'from 50% to 100%' of the condensation product.

VThe'synthetic resin formed by this processv may be used for varnish gums, for baking enamel's and japans, as solid solvents for pyroxylin, and cellulose acetate and the like. Also, as stated, it may be used as an ingredient in the formation of anv infusible -insoluble phenolic condensation product the process described in my .above men- Also -by the process herein particularly described, a manufacturer of articles formed from such an incondensation product as described, may make use of vscrap material and discarded and imperfect yarpthe proportions tioles, by causing'the saine to be transformed into a fusible product as'described herein, which fusible products may then be again utilized in the process for making theinfusible product.

' The synthetic resinl formed by my process as described herein-is fusible and soluble in many solvents asabove stated' and contains phenol and formaldehyde combined in such vproportions that the phenol is almost en-V tirely combined with the formaldehyde, and there is no excess4 or free or uncombined formaldehyde.

Having now I claim and desire to protect by Letters Patent is as follows 1.y The process of forming a tion to. take place between a phenol and formaldehyde with a small proportion of a condensing agent, with application of heat,

to form a final infusible condensation product, crushing the latter, heating to expel entrapped water and other vapors, mixing hard fusible phenol resin, consisting in causing 'a reacdescribed my invention, what with a suitable amountof phenol or-equiv- -v alent, and applying suii'l'cient heat in a closed vessel to dissolve the condensation productl therein, and maintaining the heat for a sufficient time to'reduce the product to vthe desired fusible phenolresin, and distil off .the free or unchanged phenol, substantially asdescribed. i

2. The process of forming a hard fusible phenol resin, consisting in forming a final infusible condensation product of a phenol and formaldehyde or .equivalentthereof, and causing thesaid product to dissolve in an added amount of a phenol, causing the said product to break down to a fusible phenol resin by combination with some of the said added phenol and distilling oithe excess phenol, substantially as described 3. The process of forming a hard fusible' proximately the proportion of two parts of the inal product to -one part of the phenol, and heating the mixture suiiciently to cause the said final product to break down to a fusible phenol resin b combination with some of thephenol, substantially -as described.

5. The process of 'forming a hard fusible phenol' resin, consisting in pulverizing an some of the said phenol, substantially as de- 10 infusible Afinal phenolic condensation pr0duct, mixing the same with a substance which may act as a solvent therefor at elevated temperatures, and which comprises a pheno1, and heating the mixture to a temperature of over 150o F. in a closed vessel7 until a phenol resin is formed by reaction between the said infusible condensation product and scribed.

This specification .signed and witnessed this 3d day of March, 1911.

J ONAS W. AYLSWORTH. 

